Add support for 'Cmd' argument on container tasks

lib/rake_docker/container.rb

@@ -145,7 +145,13 @@ def enhance_with_name(container, name)
     class Provisioner
       include Utilities
 
-      attr_reader :name, :image, :ports, :environment, :ready, :reporter
+      attr_reader :name,
+                  :image,
+                  :ports,
+                  :environment,
+                  :ready,
+                  :reporter,
+                  :command
 
       def initialize(name, image, opts = {})
         @name = name
@@ -154,6 +160,7 @@ def initialize(name, image, opts = {})
         @ports = opts[:ports] || []
         @ready = opts[:ready?]
         @reporter = opts[:reporter] || NullReporter.new
+        @command = opts[:command]
       end
 
       # rubocop:disable Metrics/AbcSize
@@ -165,17 +172,17 @@ def execute
           ensure_container_running(container)
         else
           reporter.container_does_not_exist(name)
-          start_new_container(name, image, ports, environment)
+          start_new_container(name, image, ports, environment, command)
         end
         reporter.done
       end
       # rubocop:enable Metrics/AbcSize
 
       private
 
-      def start_new_container(name, image, ports, environment)
+      def start_new_container(name, image, ports, environment, command)
         ensure_image_available(image)
-        create_and_start_container(name, image, ports, environment)
+        create_and_start_container(name, image, ports, environment, command)
       end
 
       def ensure_image_available(image)
@@ -206,34 +213,38 @@ def ensure_container_running(container)
         end
       end
 
-      def create_and_start_container(name, image, ports, environment)
-        start_container(create_container(image, name, ports, environment))
+      def create_and_start_container(name, image, ports, environment, command)
+        start_container(create_container(image, name, ports, environment,
+                                         command))
       end
 
-      def create_container(image, name, ports, environment)
+      def create_container(image, name, ports, environment, command)
         exposed_ports, port_bindings = process_ports(ports)
         reporter.creating_container(name, image)
         container = Docker::Container.create(
           make_container_options(
-            name, image, exposed_ports, port_bindings, environment
+            name, image, exposed_ports, port_bindings, environment, command
           )
         )
         container = enhance_with_name(container, name)
         reporter.container_created(container)
         container
       end
 
+      # rubocop:disable Metrics/ParameterLists
       def make_container_options(
-        name, image, exposed_ports, port_bindings, environment
+        name, image, exposed_ports, port_bindings, environment, command
       )
         {
           name:,
           Image: image,
           ExposedPorts: exposed_ports,
           HostConfig: { PortBindings: port_bindings },
-          Env: environment
+          Env: environment,
+          Cmd: command
         }
       end
+      # rubocop:enable Metrics/ParameterLists
 
       def start_container(container)
         reporter.starting_container(container)

lib/rake_docker/tasks/provision.rb

@@ -16,6 +16,7 @@ class Provision < RakeFactory::Task
       parameter :image, required: true
       parameter :ports
       parameter :environment
+      parameter :command
 
       parameter :ready_check
 
@@ -28,6 +29,7 @@ class Provision < RakeFactory::Task
           t.image,
           ports: t.ports,
           environment: t.environment,
+          command: t.command,
           ready?: t.ready_check,
           reporter: t.reporter
         )

spec/rake_docker/container_spec.rb

@@ -254,6 +254,70 @@
               ))
     end
 
+    it 'passes the provided command when creating the container' do
+      name = 'my-container'
+      image = 'nginx:latest'
+      command = ['ls', '-l']
+      underlying_image = instance_double(Docker::Image, image)
+      underlying_container = MockDockerContainer.created(name)
+
+      allow(Docker::Container)
+        .to(receive(:get).with(name)
+                         .and_raise(Docker::Error::NotFoundError))
+      allow(Docker::Image)
+        .to(receive(:all).with(filters: filters(image))
+                         .and_return([underlying_image]))
+      allow(underlying_container).to(receive(:start))
+      allow(Docker::Container)
+        .to(receive(:create)
+              .and_return(underlying_container))
+
+      reporter = MockReporter.new
+      provisioner = RakeDocker::Container::Provisioner
+                    .new(
+                      name, image,
+                      reporter:,
+                      command:
+                    )
+
+      provisioner.execute
+
+      expect(Docker::Container)
+        .to(have_received(:create)
+              .with(hash_including(Cmd: command)))
+    end
+
+    it 'passes nil for the command when creating container with no command' do
+      name = 'my-container'
+      image = 'nginx:latest'
+      underlying_image = instance_double(Docker::Image, image)
+      underlying_container = MockDockerContainer.created(name)
+
+      allow(Docker::Container)
+        .to(receive(:get).with(name)
+                         .and_raise(Docker::Error::NotFoundError))
+      allow(Docker::Image)
+        .to(receive(:all).with(filters: filters(image))
+                         .and_return([underlying_image]))
+      allow(underlying_container).to(receive(:start))
+      allow(Docker::Container)
+        .to(receive(:create)
+              .and_return(underlying_container))
+
+      reporter = MockReporter.new
+      provisioner = RakeDocker::Container::Provisioner
+                    .new(
+                      name, image,
+                      reporter:
+                    )
+
+      provisioner.execute
+
+      expect(Docker::Container)
+        .to(have_received(:create)
+              .with(hash_including(Cmd: nil)))
+    end
+
     # rubocop:disable RSpec/MultipleExpectations
     it 'calls the supplied readiness poller when provided' do
       name = 'my-container'

spec/rake_docker/tasks/provision_spec.rb

@@ -97,6 +97,7 @@
       'THING1' => 'one',
       'THING2' => 'two'
     }
+    command = ['ls', '-l']
     reporter = RakeDocker::Container::NullReporter.new
     ready_check = proc { true }
 
@@ -111,6 +112,7 @@
       image:,
       ports:,
       environment:,
+      command:,
       reporter:,
       ready_check:
     )
@@ -126,6 +128,7 @@
               image,
               ports:,
               environment:,
+              command:,
               reporter:,
               ready?: ready_check
             ))